1

私のJSONデータは次のようになり、「parks.json」というファイルに含まれています。

{
    "description": "Farnborough features a good amount of green space and is indeed surrounded by plenty more. Our Parks section aims to tell you, not only where they all are but a little bit about the history behind them and the people who look after them today.",
    "id": "parks",
    "name": "Parks",
    "locations": [
        {
            "name": "Queen Elizabeth Park",
            "lat": 51.29692,
            "lng": -0.76080000000000003,
            "synopsis": "Once part of Windsor Great Park"
        },
        {
            ...
        }
    ]
}

次の$resourceクエリは、上記のデータのフラグメントを取得します。

return $resource('locations/:categoryId.json', {}, {
    query: {method:'GET', params:{categoryId:'categories'}, isArray:true}
  });

渡されるcategoryIdは'parks'であるため、上記のコードはParks.jsonfile全体を取得し、それをオブジェクトにロードします。これは問題ありませんが、その一部だけを配列またはオブジェクトに抽出したいと思います。

私の質問は、場所だけを抽出するために上記をどのように適応させることができるかということです。私は特にlatとlngの値に興味があります。私はすでに他のさまざまなことを実行していて、これを行う方法にあまり精通していないので、この種のアクションを検討する必要があります。

乾杯！

4

1 に答える 1

3

A few things:

  • This probably isn't the best use of $resource. $http would be preferrable in this scenario, because you're not really dealing with a RESTful web service. You're apparently dealing with GETs on .json files. Using $resource will instantiate a bunch of extra functions and overhead you don't need and can't use.
  • The best place to filter the results you're getting back would be at the server. I know you can't really do that with a .json file, but it's worth mentioning.
  • This really isn't an issue with $resource or even Angular, so much as it is an issue with JavaScript, what you want to do is get a subset of objects from an array.

All of that said... if you must do this using $resource, you could do something like the following pseudo-code:

// a factory to create your Park resource service.
app.factory('Park', ['ngResource', function($resource) {
    //your Park resource constructor.
    var Park = $resource('locations/:categoryId.json', {}, {
        query: {method:'GET', params:{categoryId:'categories'}, isArray:true}
      });

    //a "static" function on Park to filter results.
    Park.filter = function(parks, predicate) {
        var results = [];
        for(var i = 0; i < parks.length; i++) {
            var park = parks[i];
            if(predicate(park)) {
                results.push(angular.copy(park));
            }
        }
        return results;
    };

    //return the constructor
    return Park;
}]);

// a controller example to consume your service.
app.controller('MainCtrl', function($scope, Park) {
    // get all parks in category 123
    var allParks = Park.query({categoryId: 123});

    // filter the parks down to the ones named "Hooterville Park"
    $scope.parks = Park.filter(allParks, function(park) {
        return park.name === 'Hooterville Park';
    });
});

The thing is, $resource is made to be used with a RESTful resource like so:

// create a basic resource.
var Foo = $resource('/Foo/:id');

// get and update one item.
var foo = Foo.get(123, function() {
    foo.name = 'Test';
    foo.email = 'blah@sample.com';
    foo.$save();
});

// create a new item.
var foo2 = new Foo();
foo2.name = 'New guy';
foo2.email = 'new@guy.com';
foo.$save();

// get and update a bunch of items.
var foos = Foo.query();
for(var i = 0; i < foos.length; i++) {
   var fooItem = foos[i];
   fooItem.name = 'Foo ' + i;
   fooItem.$save();
}

So unless you're going to do that stuff, I'd say go ahead and just use $http.

于 2012-11-21T02:44:47.927 に答える